How Salt Can Impact Your Blood Pressure, Heart and Kidneys

Modifying your salt intake can affect your health and longevity

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But when these bean-shaped organs sustain damage or are thrown off balance — perhaps by heavy salt intake — both your blood pressure and your heart may feel the repercussions.

Your kidneys filter more than 120 quarts of blood each day. They pull toxins and unwanted fluid from cells throughout the body, then send them to the bladder.

Eating too much salt can make it harder for your kidneys to remove fluid, which builds up in your system and increases your blood pressure.

The cycle of damage: How your heart is affected

Over time, excessive salt intake can lead to high blood pressure (hypertension), which stiffens and narrows the blood vessels. Blood and oxygen flow to key organs decreases. So the heart tries harder to pump blood throughout the body, which further increases blood pressure.

“Elevated blood pressure, particularly over a long period of time, puts an incredible strain on the heart,” says Benico Barzilai, MD, Head of Clinical Cardiology. It can enlarge the heart’s left pumping chamber and weaken the heart muscle (heart failure).

Unchecked hypertension can also damage the artery walls, which begin to collect fat, leading to heart disease and potentially heart attack or stroke.

“The best way to prevent a heart attack is to stop the arteries from becoming damaged,” says Dr. Barzilai.

What hypertension does to your kidneys

You can see this chicken-or-egg effect with high blood pressure and kidney disease as well. Hypertension puts extra pressure on the kidneys’ filtering units, which can lead to scarring. This impairs the kidneys’ ability to regulate fluid, which increases blood pressure.

“If this cycle is not stopped, it can lead to kidney disease and kidney failure,” says hypertension specialist George Thomas, MD. “High blood pressure and uncontrolled diabetes are the most common causes of kidney disease.”

Unfortunately, the vast majority of people with kidney disease don’t realize they have it. The signs and symptoms may be attributed to other conditions, and usually appear when the kidneys have already begun to fail. Here are symptoms to watch for, according to the National Kidney Foundation:

Unusual fatigue

Sleep troubles

Dry, itchy skin

Decreased urination

Blood or foam in the urine

Swelling in the ankles, feet or around the eyes

Lack of appetite

Muscle cramps

If you are experiencing any of these symptoms — particularly if you are at risk of kidney disease because you’re over age 60, have high blood pressure, have diabetes or have a family history of kidney failure — talk to your doctor about your salt intake.

The question of salt sensitivity

Salt affects people differently. “Some people can consume sodium with no effect on their blood pressure. But for others, even a slight increase in sodium intake wreaks havoc on the kidneys’ ability to regulate fluid, and increases blood pressure,” says Dr. Thomas.